I think you (@damuriajashi) are right about that, as per the SDMB rules:
Thread bumping . Thread bumping – that is, posting a short message solely to get a thread moved to the top of the thread list – is permitted once per thread only. Thanking thread participants for their contributions does not count as thread bumping.
However, some people seem to also call it a “bump” when a thread is revived for any reason after lying dormant for awhile.